Overweight employees take more time off from work for illness than staff who are within the healthy weight range, a new UK study has suggested.

The results of the study found workers classed as obese (in this case, those with a BMI above 30) took four more sick days per year on average than those of a healthy weight.

Obesity was found to increase the risk for both long-term (more than 10 days) and short-term absences.

The researchers say they hope that the findings may inspire employers to take action to encourage their employees to lose weight.

Researcher Samuel Harvey, a psychiatrist at King’s College London, said: “Employers are in quite a unique position to contribute to the public health message and interventions around obesity and trying to reduce levels of obesity.

“Our hope is that by demonstrating the economic cost to them of obesity amongst their workforce that that will help motivate employers to get involved in thinking about this problem.”

Harvey and his colleagues analysed data from 625 London Underground staff. The workers either drove or controlled trains, and were required to undergo regular health check-ups.

Obese workers took an average of nine days off work per year while healthy weight individuals took off an average of five.

It might be that obese people are more susceptible to infections and take longer to recover from them, Harvey suggested.

He added: “Obese individuals might cope with symptoms of ill health in different ways to those of healthy weight, causing them to have a lower threshold for taking time off.”

The study was published in the August issue of the journal Occupational Medicine.